Limits...
Curcumin inhibits glyoxalase 1: a possible link to its anti-inflammatory and anti-tumor activity.

Santel T, Pflug G, Hemdan NY, Schäfer A, Hollenbach M, Buchold M, Hintersdorf A, Lindner I, Otto A, Bigl M, Oerlecke I, Hutschenreuther A, Hutschenreuter A, Sack U, Huse K, Groth M, Birkemeyer C, Schellenberger W, Gebhardt R, Platzer M, Weiss T, Vijayalakshmi MA, Krüger M, Birkenmeier G - PLoS ONE (2008)

Bottom Line: Results of enzyme kinetics revealed that curcumin, compared to the polyphenols quercetin, myricetin, kaempferol, luteolin and rutin, elicited a stronger competitive inhibitory effect on Glo1 (K(i) = 5.1+/-1.4 microM).Moreover, whereas curcumin was found to hamper the growth of breast cancer (JIMT-1, MDA-MB-231), prostate cancer PC-3 and brain astrocytoma 1321N1 cells, no effect on growth or vitality of human primary hepatocytes was elucidated.The results described herein provide new insights into curcumin's biological activities as they indicate that inhibition of Glo1 by curcumin may result in non-tolerable levels of MGO and GSH, which, in turn, modulate various metabolic cellular pathways including depletion of cellular ATP and GSH content.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biochemistry, University of Leipzig, Leipzig, Germany.

ABSTRACT

Background: Glyoxalases (Glo1 and Glo2) are involved in the glycolytic pathway by detoxifying the reactive methylglyoxal (MGO) into D-lactate in a two-step reaction using glutathione (GSH) as cofactor. Inhibitors of glyoxalases are considered as anti-inflammatory and anti-carcinogenic agents. The recent finding that various polyphenols modulate Glo1 activity has prompted us to assess curcumin's potency as an Glo1 inhibitor.

Methodology/principal findings: Cultures of whole blood cells and tumor cell lines (PC-3, JIM-1, MDA-MD 231 and 1321N1) were set up to investigate the effect of selected polyphenols, including curcumin, on the LPS-induced cytokine production (cytometric bead-based array), cell proliferation (WST-1 assay), cytosolic Glo1 and Glo2 enzymatic activity, apoptosis/necrosis (annexin V-FITC/propidium iodide staining; flow cytometric analysis) as well as GSH and ATP content. Results of enzyme kinetics revealed that curcumin, compared to the polyphenols quercetin, myricetin, kaempferol, luteolin and rutin, elicited a stronger competitive inhibitory effect on Glo1 (K(i) = 5.1+/-1.4 microM). Applying a whole blood assay, IC(50) values of pro-inflammatory cytokine release (TNF-alpha, IL-6, IL-8, IL-1beta) were found to be positively correlated with the K(i)-values of the aforementioned polyphenols. Moreover, whereas curcumin was found to hamper the growth of breast cancer (JIMT-1, MDA-MB-231), prostate cancer PC-3 and brain astrocytoma 1321N1 cells, no effect on growth or vitality of human primary hepatocytes was elucidated. Curcumin decreased D-lactate release by tumor cells, another clue for inhibition of intracellular Glo1.

Conclusions/significance: The results described herein provide new insights into curcumin's biological activities as they indicate that inhibition of Glo1 by curcumin may result in non-tolerable levels of MGO and GSH, which, in turn, modulate various metabolic cellular pathways including depletion of cellular ATP and GSH content. This may account for curcumin's potency as an anti-inflammatory and anti-tumor agent. The findings support the use of curcumin as a potential therapeutic agent.

Show MeSH

Related in: MedlinePlus

Effect of methylglyoxal on proliferation of astrocytoma and breast cancer cells.Astrocytoma 1321N1 (5000 cells/well) and breast cancer cells JIMT-1 were seeded (start) and cultured in the absence or presence of increasing concentrations of MGO for 24 h. Cell vitality was recorded by WST-1 assay. Data represent the mean±S.D. of independent experiments (n = 12).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2567432&req=5

pone-0003508-g006: Effect of methylglyoxal on proliferation of astrocytoma and breast cancer cells.Astrocytoma 1321N1 (5000 cells/well) and breast cancer cells JIMT-1 were seeded (start) and cultured in the absence or presence of increasing concentrations of MGO for 24 h. Cell vitality was recorded by WST-1 assay. Data represent the mean±S.D. of independent experiments (n = 12).

Mentions: Because MGO rapidly forms hemithioacetal with GSH, elevated MGO will, in turn, deplete cellular GSH levels especially at low expression level of Glo2. Therefore, we investigated whether MGO may, at least partially, account for the anti-proliferative effect of curcumin by treating 1321N1 and JIMT-1cells with increasing concentrations of the reactive aldehyde (Fig. 6). The results disclose the anti-proliferative properties of MGO. Because MGO exerts its effect predominantly intracellular, we expected that the concentration of MGO that reaches the cell is much lower than what was added to the medium. This means that MGO rapidly reacts with amino and sulfhydryl groups of proteins abundantly present in the culture medium (10% fetal calf serum). In this regard, it has been reported that the intracellular concentrations of MGO in normal growing cells can be elevated up to 300 µM [23].


Curcumin inhibits glyoxalase 1: a possible link to its anti-inflammatory and anti-tumor activity.

Santel T, Pflug G, Hemdan NY, Schäfer A, Hollenbach M, Buchold M, Hintersdorf A, Lindner I, Otto A, Bigl M, Oerlecke I, Hutschenreuther A, Hutschenreuter A, Sack U, Huse K, Groth M, Birkemeyer C, Schellenberger W, Gebhardt R, Platzer M, Weiss T, Vijayalakshmi MA, Krüger M, Birkenmeier G - PLoS ONE (2008)

Effect of methylglyoxal on proliferation of astrocytoma and breast cancer cells.Astrocytoma 1321N1 (5000 cells/well) and breast cancer cells JIMT-1 were seeded (start) and cultured in the absence or presence of increasing concentrations of MGO for 24 h. Cell vitality was recorded by WST-1 assay. Data represent the mean±S.D. of independent experiments (n = 12).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2567432&req=5

pone-0003508-g006: Effect of methylglyoxal on proliferation of astrocytoma and breast cancer cells.Astrocytoma 1321N1 (5000 cells/well) and breast cancer cells JIMT-1 were seeded (start) and cultured in the absence or presence of increasing concentrations of MGO for 24 h. Cell vitality was recorded by WST-1 assay. Data represent the mean±S.D. of independent experiments (n = 12).
Mentions: Because MGO rapidly forms hemithioacetal with GSH, elevated MGO will, in turn, deplete cellular GSH levels especially at low expression level of Glo2. Therefore, we investigated whether MGO may, at least partially, account for the anti-proliferative effect of curcumin by treating 1321N1 and JIMT-1cells with increasing concentrations of the reactive aldehyde (Fig. 6). The results disclose the anti-proliferative properties of MGO. Because MGO exerts its effect predominantly intracellular, we expected that the concentration of MGO that reaches the cell is much lower than what was added to the medium. This means that MGO rapidly reacts with amino and sulfhydryl groups of proteins abundantly present in the culture medium (10% fetal calf serum). In this regard, it has been reported that the intracellular concentrations of MGO in normal growing cells can be elevated up to 300 µM [23].

Bottom Line: Results of enzyme kinetics revealed that curcumin, compared to the polyphenols quercetin, myricetin, kaempferol, luteolin and rutin, elicited a stronger competitive inhibitory effect on Glo1 (K(i) = 5.1+/-1.4 microM).Moreover, whereas curcumin was found to hamper the growth of breast cancer (JIMT-1, MDA-MB-231), prostate cancer PC-3 and brain astrocytoma 1321N1 cells, no effect on growth or vitality of human primary hepatocytes was elucidated.The results described herein provide new insights into curcumin's biological activities as they indicate that inhibition of Glo1 by curcumin may result in non-tolerable levels of MGO and GSH, which, in turn, modulate various metabolic cellular pathways including depletion of cellular ATP and GSH content.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biochemistry, University of Leipzig, Leipzig, Germany.

ABSTRACT

Background: Glyoxalases (Glo1 and Glo2) are involved in the glycolytic pathway by detoxifying the reactive methylglyoxal (MGO) into D-lactate in a two-step reaction using glutathione (GSH) as cofactor. Inhibitors of glyoxalases are considered as anti-inflammatory and anti-carcinogenic agents. The recent finding that various polyphenols modulate Glo1 activity has prompted us to assess curcumin's potency as an Glo1 inhibitor.

Methodology/principal findings: Cultures of whole blood cells and tumor cell lines (PC-3, JIM-1, MDA-MD 231 and 1321N1) were set up to investigate the effect of selected polyphenols, including curcumin, on the LPS-induced cytokine production (cytometric bead-based array), cell proliferation (WST-1 assay), cytosolic Glo1 and Glo2 enzymatic activity, apoptosis/necrosis (annexin V-FITC/propidium iodide staining; flow cytometric analysis) as well as GSH and ATP content. Results of enzyme kinetics revealed that curcumin, compared to the polyphenols quercetin, myricetin, kaempferol, luteolin and rutin, elicited a stronger competitive inhibitory effect on Glo1 (K(i) = 5.1+/-1.4 microM). Applying a whole blood assay, IC(50) values of pro-inflammatory cytokine release (TNF-alpha, IL-6, IL-8, IL-1beta) were found to be positively correlated with the K(i)-values of the aforementioned polyphenols. Moreover, whereas curcumin was found to hamper the growth of breast cancer (JIMT-1, MDA-MB-231), prostate cancer PC-3 and brain astrocytoma 1321N1 cells, no effect on growth or vitality of human primary hepatocytes was elucidated. Curcumin decreased D-lactate release by tumor cells, another clue for inhibition of intracellular Glo1.

Conclusions/significance: The results described herein provide new insights into curcumin's biological activities as they indicate that inhibition of Glo1 by curcumin may result in non-tolerable levels of MGO and GSH, which, in turn, modulate various metabolic cellular pathways including depletion of cellular ATP and GSH content. This may account for curcumin's potency as an anti-inflammatory and anti-tumor agent. The findings support the use of curcumin as a potential therapeutic agent.

Show MeSH
Related in: MedlinePlus